This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A171154 Smallest prime whose decimal expansion begins with concatenation of first n primes in descending order. 5

%I

%S 2,3203,5323,75323,11753221,131175329,171311753203,19171311753229,

%T 231917131175321,292319171311753231,3129231917131175327,

%U 3731292319171311753239,41373129231917131175321

%N Smallest prime whose decimal expansion begins with concatenation of first n primes in descending order.

%C (1) Sequence is conjectured to be infinite

%C (2) a(n) ="p(n)...p(1) R(n)"

%C (3) R(n) for n>1: "03", 3, 3, 21, 9, "03", 29, 1, 31, 7, 39, 1, 33, 69, 23, 3, 59, 27, ...

%C (4) It is conjectured that R(n)=1 for infinite many n

%D Leonard E. Dickson: History of the Theory of numbers, vol. I, Dover Publications 2005

%e a(1)=2=prime(1) is the exceptional case, because no R(1)

%e a(2)=3203=prime(453) = "32 03", R(2)="03"

%e a(5)=11753221=prime(772902) = "p(5)...p(1) 21", R(5)=21

%Y Cf. A000040, A066065, A019518, A089710, A053546

%K nonn,base

%O 1,1

%A Ulrich Krug (leuchtfeuer37(AT)gmx.de), Dec 04 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified May 24 20:57 EDT 2013. Contains 225631 sequences.